In recent years, semiconductors or other electronic devices have been in a rapid progress toward scale-down, necessitating high-precision processing. Among such fine processing techniques, a common one is deposition methods using a sputtering process, in particular, for a thin film formation process. The sputtering process is a process that with a plasma generated by making gas discharge occurring in a vacuum atmosphere, cations of the plasma are allowed to collide with a target (or sputtering target) placed at a negative electrode which is a so called sputtering electrode so that particles sputtered by the collisions adhere to a substrate to be processed, by which a thin film is formed.
Such sputtering processes are widely used in deposition processes by virtue of their easiness in composition control or device operability. Whereas the target in a deposition process is in many cases a plate-shaped one, it is unlikely that the target surface is uniformly depleted. This poses an issue that the use efficiency of the target material degrades. To solve this issue, in recent years, there have been penetrating techniques using powdery or granular targets such as shown in FIGS. 10 and 11 (see, e.g., Document 1: Japanese unexamined patent publication No. H09-176845 A, and Document 2: Japanese unexamined patent publication No. H10-036962 A).
In a sputtering apparatus 500 shown in FIG. 10, a granular target material 502 is set within a target mounting plate 501 placed within a processing chamber 508. Then, with electric power applied from an RF-power supply 510 through a matching box 511, plasma is generated in the processing chamber 508, by which deposition processing by sputtering is carried out.
In a sputtering apparatus 600 shown in FIG. 11, vibrations are imparted to a target mounting plate 601 by a vibration generator 609 so that planarization of a granular target 602 that has been nonuniformly depleted after the sputtering process can be achieved.
Further, there have been provided a reactive sputtering apparatus, as shown in FIG. 12, in which a plate-like target 702 having a plurality of small holes 702a is set on a target mounting base 701 having small holes intended for use of gas introduction, in which state sputtering is carried out (see, e.g., Document 3: Japanese unexamined patent publication No. H05-065642 A), and another apparatus, as shown in FIGS. 13A and 13B, which is intended for use of a complex target in which embedment objects 803 made of different-composition ingredients are embedded in a plurality of hole portions provided in a target plate 802 (see, e.g., Document 4: Japanese unexamined patent publication No. H02-085360 A).